Add tests for fixed issues

Fixes #23037.
Fixes #25339.

src/test/compile-fail/issue-23073.rs

@@ -0,0 +1,17 @@
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+trait Foo { type T; }
+trait Bar {
+    type Foo: Foo;
+    type FooT = <<Self as Bar>::Foo>::T; //~ ERROR ambiguous associated type
+}
+
+fn main() {}

src/test/run-pass/issue-25339.rs

@@ -0,0 +1,36 @@
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use std::marker::PhantomData;
+
+pub trait Routing<I> {
+    type Output;
+    fn resolve(&self, input: I);
+}
+
+pub trait ToRouting {
+    type Input;
+    type Routing : ?Sized = Routing<Self::Input, Output=()>;
+    fn to_routing(self) -> Self::Routing;
+}
+
+pub struct Mount<I, R: Routing<I>> {
+    action: R,
+    _marker: PhantomData<I>
+}
+
+impl<I, R: Routing<I>> Mount<I, R> {
+    pub fn create<T: ToRouting<Routing=R>>(mount: &str, input: T) {
+        input.to_routing();
+    }
+}
+
+fn main() {
+}